Thread-twisting apparatus with dual thread guide

ABSTRACT

A thread-twisting apparatus has a hollow stem through which the threads to be twisted together are drawn axially. A pair of axially spaced thread brakes are provided in the stem, and a hub carrying a thread guide is rotationally mounted on the stem. This guide is a bent wire having a C-shaped central portion embracing the hub and formed with an inwardly directed finger engaging in a radially open hole in the hub for rotational coupling of the hub and guide. A rotation brake acts on the hub and the adjustment for this brake and for one of the thread brakes can be carried out in a single operation whereby both braking effects are either increased or decreased simultaneously.

Jan. 8, 1974 United States Patent 1191 Greive et al.

[ THREAD-TWISTING APPARATUS WITH DUAL THREAD GUIDE [75] Inventors: Aloys Greive; Aloys Treus, both of Westfalia, Germany.

[73] Assignee: Hamel GmbH Zwirnmaschinen,

725,283 3/1955 Great Britain..................... 57/58.86

Munster/Westf., Germany June 19, 1972 v 22 Filed:

Primary Examiner-John Petrakes App! 264,280 Assistant Examiner-Charles Gorenstein Att0rney--Karl F. Ross Related US. Application Data [63] Continuation-impart of Ser. No. 188,335, Oct. 12,

[57] ABSTRACT A thread-twisting apparatus has a hollow stem through [30] Foreign Application Priority Data June 21, 1971 which the threads to be twisted together are drawn axially. A pair of axially spaced thread brakes are pro- Germany 0 71 23 827.2 1 vided in the stem, and a hub carrying a thread guide, is [521 (LS. 57/58.52, 57/58.86, 57/106, ro ationally mounted on the. stem. This guide is a bent wire having a C-shaped central portion embracing the Int. Cl...... hub and formed with an inwardly directed finger en- [58] gaging in a radially open hole in the hub for rotational coupling of the hub and guide. A rotation brake acts v on the hub and the adjustment for this brake and for one of the thread brakes can be carried out in a single References Cited UNITED STATES PATENTS 12/1922 operation whereby both braking effects'are eitherincreased or decreased simultaneously.

Kaufman.....,...........,.....,..

57/116 X 13 Claims, 4 Drawing Figures sum 2 er 2 FIG.3

TI-IREAD-TWISTING APPARATUS WITH DUAL THREAD GUIDE CROSS-REFERENCE TO RELATED APPLICATION This application is a'continuation-in-part of our copending application Ser. No. 188,335 filed 12 Oct. 1971 for YARN-TWISTING APPARATUS FOR FOR- MATION OF MULTIPLE-PLY THREAD.

FIELD OF THE INVENTION The present invention relates to an appartus for twisting yarns. More specifically this invention concerns a yarn guiding and tensioning arrangement for a double spool, two-thread yarn twisting arrangement of the type in which two threads are passed through a central tube.

BACKGROUND OF THE INVENTION In the twisting together of a pair of filaments, two bobbins or spools are mounted one above the other on a common axis. A filament is drawn upwardly from the two bobbins, which are prevented from rotating, and

then down through a vertical passage in a stem on which the bobbins are mounted. Thence the two threads pass radially 'out through a side of a spindle onto a rotating drum where they are twisted. From the drum these now twisted filaments are pulled upwardly, forming a balloon around the bobbins. A takeup spool serves to wind up the threads which have been twisted together to an extent determined by the takeup speed and the rotation speed of the flyer. Commonly assigned patent application Ser. No. 34,007 filed 4 May 1970 describes such a system (now U.S. Pat. No. 3,648,489).

Our commonly assigned patent application Ser. No. 188,335, mentioned above, describes a system of this type characterized by the provision of a second independent thread brake, in the upper end of the spindle. Such a brake comprises a gravity-loaded ball resting in a conical seat to pinch and tension the yarns as they are pulled between the ball and the seat. The yarns are further tensioned in the lower region of the spindle by a second thread brake comprising a bullet-shaped body which has a pair of rounded ends and which is compressed between two opposite and axially directed conical seats, the yarns being pinched at each end of the body between it and the seats.

According to this earlier application the compressed body comprises a pair of telescoping cylindrical sleeves with hemispherical ends and a compression spring received between these sleeves to urge them outwardly toward their respective seats. In addition the upper seat is formed on the lower end of an elongated element threaded into the nonrotatable spindle, theupper end of the element being provided with markings cooperating with a scale. The element is threaded in the spindle so that rotation of it relative to the spindle moves the upper seat axially relative to the lower seat, compressing the spring in the brake body more or less to vary the braking effect. The upper brake'is mounted on this adjustment element, which itself is hollow.

OBJECTS OF THE INVENTION It is an object of the present invention to advance the principles disclosed in our earlier application Ser. No. 188,335 and provide a further-improved threadtwisting apparatus Another object of the present invention is the provision of a thread-twisting apparatus wherein the threads or filaments are pulled off their respective bobbins in such a manner that their fouling together is virtually impossible and in such a manner that, on thread breakage, an excessive length of these filaments is not wound around the bobbins several times.

SUMMARY OF THE INVENTION These objects are attained according to the present invention by an apparatus .whose hollow spindle is provided with a hub that can rotate relative to the spindle, a brake being provided between the rotatable hub and the nonrotatable spindle. A thread guide is removably mounted on this hub so that the device may be used for twisting a single filament or for twisting two or more filaments, depending on how-many eyes are provided in this guide.

Such an apparatus is especially advantageous in installations where sometimes one and sometimes several yarns are to be twisted since simple removal or mounting of the guide allows the changeover to be executed in seconds. Such a guide is necessary to keep the two filaments apart until theyenter the upright axial passage through the stem since if they touch each other just as they are being pulled from their respective bobbins it is almost inevitable that they will foul and completely upset the twisting operation.

According to a feature of this invention the hub is formed with a circumferential outwardly open groove and with a radial notch opening intothis groove. The flyer is a bent wire having a pair of arms each formed at the end with a thread-guiding eye-and both joined together at the center by a C-shaped region which snaps into the groove in the hub. In addition this C-shaped central region is formed with an inwardly directed spike-like portion which is received in the notch and rotationally couples the flyer to its hub.

In accordance with yet another feature of this invention the hub is carried on a hollow upright tube through which the filament passes. A friction member rotationally coupled to the tube engages the upper side of the hub and another such member mounted below the hub engages its bottom. A nut is threaded in the lower member and is nonrotatable relative to the tube which itself is displaceable axially between two positions in be called its adjustment position in which it is rotatable relative to the lower support member, its rotation will screw the nut in the lower member, displacing it therein.

A cartridge-type thread brake comprising an'axially resiliently compressible body bears in one direction on a seat formed in the lower member and in the other direction on a seat formed on the lower end of the tube which is downwardly biased by a spring engaging the above mentioned nut. Thus when the tube is moved into its adjustment position and rotated it varies the pressure which the spring exerts onthe compressible cartridge by displacing the nut axially.

. Another spring is provided between the upper member and the friction ring bearing against the top of the hub. Since the pressure exerted on the cartridge by its spring determines how far into the lower member the tube projects, the compression of the spring bearing on the hub is affected as the thread brake is adjusted. As the thread brake is loosened the tube rises in the lower member, which decompresses the spring bearing on the hub. On original assembly a specific ratio is established between these two springs, with this ratio remaining essentially constant on adjustment of the device.

DESCRIPTION OF THE DRAWING The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1A is a vertical section through a first embodiment of the apparatus, according to the present invention, in the operative position;

FIG. 1B is a similar section showing another embodiment of the device in the adjustment position;

FIG. 2 is a section taken along line II-II of FIG. 1A; and

FIG. 3 is a perspective view illustating how the apparatus according to the present invention is employed.

SPECIFIC DESCRIPTION With reference to FIG. 3 a pair of bobbins 47 and 48 of yarn are mounted one above the other on a common stem 11 and their respective filaments 47' and 48 are drawn through eyes in the end of a guide 49 carried on a hub 39 rotatable on this stem 11. Thence the two filaments 47 and 48 are drawn through this stem 11 and pass out through a hole 50 in a flyer 50 which is driven by a motor 51. This twists the two filaments together. Thereafter they pass up around the entire assembly forming a ballon and through an eyelet 52 to a takeup spool 53 driven by a motor 54. The amount of twist imparted to the two filaments is determined by the rotation rate of the flyer 50 and the takeup speed of the spool 53. The spindle 11 is prevented by magnets or the like from rotating and contains two thread brakes which maintain a predetermined amount of tension in the filaments to ensure even twisting and to prevent the balloon from becoming excessively large.

As shown in FIG. 1A and 1B, the stem 11 is mounted on a support rod 12 which is carried on the flyer 50 and carries a lower sleeve member 13 and a seat 14 with a conical surface for a cartridge brake 15. This brake 15 is an axially elongatable cartridge formed by two telescoping sleeves 15 and 15" between which is provided a compression spring 15", each sleeve and sleeve 15' having a hemispherical end bearing on its respective conical seat.

A tube 17 has its lower end received in the lower member 13 and passes through a cover 19 into the lower end of an upper sleeve member 29 to which it is rotationally secured by a set screw 30. This tube 17 is provided with a snap ring 20 which prevents it from being pulled axially out of the lower member 13 by engagement with the screwed-on cover cap 19. In addition an axial groove 21 is formed in the tube 17 into which fits a tongue on an adjustment nut 24 which is threaded into the lower member 13 and surrounds the tube 17. Thus the tube 17 and the nut 24 are rotationally coupled in all possible axial positions of the tube 17 relative to the lower member 13 as defined by the snap ring 20.

The tube 17 carries on its lower end a seat 16 for the upper hemispherical end of the braking body 15 and a ring 22 which is rotationally coupled to this seat element 16 and which is formed with axially extending fins fitting into complementary grooves 46 formed on the inside of the lower member 13. These grooves 46 only extend part of the way up in the member 13 so that in the FIG. 1A position the ring 22 fits into them and is 7 therefore rotationally coupled to them whereas in the FIG. 1B position (adjustment position) they do not engage each other and therefore the tube 17 can rotate relative to the element 13. A compression spring 23 surrounding the tube 17 is braced between the ring 22 and the nut 24 to pull the tube 17 down into the lower member 13 with a force determined by how much it is compressed by the nut 24, and of course by how much its spring force is greater than that of the spring 15" in resilient brake body 15. The upper member 29 is provided at its top with a threaded-in receiving eye 33. FIG. 1A shows how a ball brake 31 as described in the abov e iiieiifioned Ser. No. 1881335 application can be used here. Alternately, as shown in FIG. 18, a cartridge brake 32 identical to the brake 15 may be employed,

in which case the distance by which eye 33 is screwed into the member 29 determines the degree to which it is compressed and, therefore, and the magnitude of the tension it imparts to the thread whose path is shown at .T. In both cases a seat 28 is provided at the upper end of the tube 17 for the brake. All of the seats 14, 16, 28, and even 33 can be made of a synthetic-resin material or a particular metal whose friction characteristics are especially adapted to the particular needs.

The hub 39 for the wire guide 49 (FIG. 2) is carried between the elements 13 and 29. This hub is a short sleeve which is rotatable relative to the tube. 17 and which rides on the cap 19 via a friction washer 38 and against whose top another washer 35 bears. The member 29 receives the upper end of the hub 39 at 34. The inner walls of this member 29 are once again formed with grooves 37 which interfit with the washer 35 so that the washer 35 is rotationally coupled to it. In addition a spring 36 is braced between the washer 35 and the member 29 to urge this washer 35 against the hub and thereby brake its rotation relative to the member 29. A radially inwardly extending projector 43 of the wire guide extends into a radially outwardly open hole 43' of the hub.

In order to adjust the upper brake 31 the eye 33 is removed and a heavier or lighter ball is exchanged with the existing ball. The brake 32 is adjusted by screwing the eye 33 in or out.

The brake 15 is adjusted by grasping the upper member 29 and lifting it until the ring 22 is pulled out of engagement with the grooves 46 in the lower member 13. Then, while holding the device in this adjustment position as shown in FIG. 13 with the spring 23 compressed, the upper member 29 is rotated relative to the lower member 13 to screw the nut 24 in the lower member 13. Screwing the nut 24 down in this lower member 13 will compress the cartridge 15 more and thereby increase the braking effect and vice versa.

At the same time that the braking effect in the brake 15 is increased the braking effect exerted by friction washer 35 on the hub 39 is increased and vice versa. This is because, with increasing compression of spring 23 the capsule or cartridge 15 will be more compressed and therefore the tube 17 will extend further into the lower member 13. Since this tube 17 drops and the hub 39 (FIG. 2) cannot, the upper member 29 will therefore compress the spring 36 more and cause greater braking on the thread guide to take place. Decreasing of the braking effect at brake 15 similarly decreases the braking effect on the hub 39. Since the braking effects both so adjusted are mainly responsible for the degree of tension in thread, it is extremely advantageous that they be adjustable in one operation.

We claim:

1. A guiding and braking arrangement for a threadtwisting apparatus comprising:

an axially elongated hollow stem;

a pair of axially spaced thread brakes in said stern;

a hub rotatably mounted on said stem;

a thread guide removably mounted on and rotationally fixed to said hub; and means for braking rotation of said hub relative to said stem, said guide being a bent wire having a C- shaped central portion snugly embracing said hub.

2. The arrangement defined in claim 1 wherein said hub is formed with a radially open hole, said guide being provided in said portion with a radially inwardly extending projection receivable in said hole.

3. The arrangement defined in claim 2 wherein said guide has a pair of substantially diametrically opposite arms each provided with a thread-receiving eye.

4. The arrangement defined in claim 1, further comprising means interconnecting one of said thread brakes with said braking means for simultaneous adjustment of both.

5. The arrangement defined in claim 4 wherein said one of said thread brake comprises a pair of axially open conical seats and a compressible body engaged there between.

6. The arrangement defined in claim 5 wherein said braking means includes a first spring bearing axially against said hub.

7. The arrangement defined in claim 6 wherein said means interconnecting said one brake to said braking means includes:

an axially elongated tube in said stem carrying an abutment, and provided at one end with one of said seats of said one brake, said first spring bearing against said abutment and against said hub;

a nut threaded into said stem and formed with a central hole, said tube passing through said central hole;

means rotationally coupling said tube to said nut for rotation and axial displacement of said nut relative to said'stem on rotation of said tube;

a second spring braced between said nut and said one seat whereby axial displacement of said nut changes the pressure exerted by said one seat on said body and thereby axially displaces said tube; and

means for pennitting rotation of said tube relative to said stem in a first axial position of said tube and for pro-venting rotation therebetween in a second axial position of said tube.

8. The arrangement definedin claim 7 wherein said hub has one end turned toward said one seat and an end turned away there-from, said first spring bearing against said end turned away therefrom.

9. A guiding and braking arrangement for a threadtwisting apparatus comprising:

an axially elongated hollow stem;

a pair of axially spaced thread brakesin said stem;

a hub rotatably mounted on said stem;

a thread guide removably mounted on and rotationally fixed to said hub;

means for braking rotation of said hub relative to said stern; and

means interconnecting one of said thread brakes with said braking means for simultaneous adjustment of both, said one of said thread brakes comprising a pair of axially open conical seats and a compressible body engaged there between.

10. The arrangement defined in claim 9 wherein said braking means includes a first spring bearing axially against said hub.

11. The arrangement defined in claim 10 wherein said means interconnecting said one brake to said braking means includes:

an axially elongated tube in said stem carrying an abutment, and provided at one end with one of said seats of said one brake, said first spring bearing against said abutment and against said hub;

a nut threaded into said stern and formed with a central hole, said tube passing through said central hole;

means rotationally coupling said tube to said nut for rotation and axial displacement of said nut relative to said stem on rotation of said tube;

a second spring braced between said nut and said one seat whereby axial displacement of said nut changes the pressure exerted by said one seat on said body and thereby axially displaces said tube; and

means for permitting rotation of said tube relative to said stem in a first axial position of'said tube and for pre-venting rotation therebetween in a second axial position of said tube.

12. The arrangement defined in claim 11 wherein said hub has one end turned toward said one seat and an end turned away therefrom, said first spring bearing against said end turned away therefrom.

13. The arrangement defined in claim 12 for a double-spool two-thread twisting machine, wherein said means rotationally coupling said tube to said nut and said means for permitting rotation and for preventing rotation of said tube both include axially extending interfitting formations on said tube, nut and stern, said guide being unitarily bent from a single wire with a spreadable C-shaped central protion, a pair of arms extending outwardly from said central portion, and a pair of guide eyes bent into the ends of said arms, said hub having a portion of noncircular cross-section releasably engageable by said central portion of said wire for rotational coupling of said wire to said hub. 

1. A guiding and braking arrangement for a thread-twisting apparatus comprising: an axially elongated hollow stem; a pair of axially spaced thread brakes in said stem; a hub rotatably mounted on said stem; a thread guide removably mounted on and rotationally fixed to said hub; and means for braking rotation of said hub relative to said stem, said guide being a bent wire having a C-shaped central portion snugly embracing said hub.
 2. The arrangement defined in claim 1 wherein said hub is formed with a radially open hole, said guide being provided in said portion with a radially inwardly extending projection receivable in said hole.
 3. The arrangement defined in claim 2 wherein said guide has a pair of substantially diametrically opposIte arms each provided with a thread-receiving eye.
 4. The arrangement defined in claim 1, further comprising means interconnecting one of said thread brakes with said braking means for simultaneous adjustment of both.
 5. The arrangement defined in claim 4 wherein said one of said thread brake comprises a pair of axially open conical seats and a compressible body engaged there between.
 6. The arrangement defined in claim 5 wherein said braking means includes a first spring bearing axially against said hub.
 7. The arrangement defined in claim 6 wherein said means interconnecting said one brake to said braking means includes: an axially elongated tube in said stem carrying an abutment, and provided at one end with one of said seats of said one brake, said first spring bearing against said abutment and against said hub; a nut threaded into said stem and formed with a central hole, said tube passing through said central hole; means rotationally coupling said tube to said nut for rotation and axial displacement of said nut relative to said stem on rotation of said tube; a second spring braced between said nut and said one seat whereby axial displacement of said nut changes the pressure exerted by said one seat on said body and thereby axially displaces said tube; and means for permitting rotation of said tube relative to said stem in a first axial position of said tube and for pre-venting rotation therebetween in a second axial position of said tube.
 8. The arrangement defined in claim 7 wherein said hub has one end turned toward said one seat and an end turned away there-from, said first spring bearing against said end turned away therefrom.
 9. A guiding and braking arrangement for a thread-twisting apparatus comprising: an axially elongated hollow stem; a pair of axially spaced thread brakes in said stem; a hub rotatably mounted on said stem; a thread guide removably mounted on and rotationally fixed to said hub; means for braking rotation of said hub relative to said stem; and means interconnecting one of said thread brakes with said braking means for simultaneous adjustment of both, said one of said thread brakes comprising a pair of axially open conical seats and a compressible body engaged there between.
 10. The arrangement defined in claim 9 wherein said braking means includes a first spring bearing axially against said hub.
 11. The arrangement defined in claim 10 wherein said means interconnecting said one brake to said braking means includes: an axially elongated tube in said stem carrying an abutment, and provided at one end with one of said seats of said one brake, said first spring bearing against said abutment and against said hub; a nut threaded into said stem and formed with a central hole, said tube passing through said central hole; means rotationally coupling said tube to said nut for rotation and axial displacement of said nut relative to said stem on rotation of said tube; a second spring braced between said nut and said one seat whereby axial displacement of said nut changes the pressure exerted by said one seat on said body and thereby axially displaces said tube; and means for permitting rotation of said tube relative to said stem in a first axial position of said tube and for pre-venting rotation therebetween in a second axial position of said tube.
 12. The arrangement defined in claim 11 wherein said hub has one end turned toward said one seat and an end turned away therefrom, said first spring bearing against said end turned away therefrom.
 13. The arrangement defined in claim 12 for a double-spool two-thread twisting machine, wherein said means rotationally coupling said tube to said nut and said means for permitting rotation and for preventing rotation of said tube both include axially extending interfitting formations on said tube, nut and stem, said guide being unitarily bent from a single wire with a spreadable C-shaped central protioN, a pair of arms extending outwardly from said central portion, and a pair of guide eyes bent into the ends of said arms, said hub having a portion of noncircular cross-section releasably engageable by said central portion of said wire for rotational coupling of said wire to said hub. 